DOI QR코드

DOI QR Code

The Dose and Risk Reduction from Adoption of Automatic mA Control in 4D CT Scans

자동전류조절기능을 사용한 4D CT 촬영시 선량 및 위험도 저감 효과

  • Ko, Young Eun (Department of Radiation Oncology, Ulsan University Hospital, University of Ulsan College of Medicine) ;
  • Je, Hyoung Uk (Department of Radiation Oncology, Ulsan University Hospital, University of Ulsan College of Medicine) ;
  • Hwang, Yeon (Department of Neurosurgery, Ulsan University Hospital, University of Ulsan College of Medicine) ;
  • Park, Sung Ho (Department of Neurosurgery, Ulsan University Hospital, University of Ulsan College of Medicine)
  • 고영은 (울산대학교 의과대학 울산대학교병원 방사선종양학교실) ;
  • 제형욱 (울산대학교 의과대학 울산대학교병원 방사선종양학교실) ;
  • 황연 (울산대학교 의과대학 울산대학교병원 신경외과학교실) ;
  • 박성호 (울산대학교 의과대학 울산대학교병원 신경외과학교실)
  • Received : 2015.12.09
  • Accepted : 2015.12.22
  • Published : 2015.12.31

Abstract

In this study, the reduction of dose and risk was evaluated from using automatic mA control in 4D CT scan of patients whose organ movement was considered for gated radiotherapy. The organ doses, CTDI, effective doses from 4D CT with and without using automatic mA control were evaluated using CT-Expo program for each 10 patients of liver and lung cancer, and the risk of exposure induced death and loss of life expectancy were evaluated using PCXMC program. It was founded that there were 26.8%, and 15.5% dose reduction in organ doses and CTDI for liver and lung cancer patients and 16.5% and 19.8% risk reduction in liver and lung cancer patients. The organ doses and effective doses were evaluated for the parameter of each patient used in CT scans, and risks considering age and gender could be evaluated. It was founded that there were 21.2% dose reduction and 18.2% risk reduction in 4D CT scan using AEC for liver and lung cancer patients.

본 연구는 호흡에 따른 장기의 움직임을 고려하는 치료를 계획하는 4D CT를 촬영하는 환자에게 자동전류조절기능을 사용함에 따른 선량 및 위험도 감소를 평가하고자 하였다. 자동전류조절기능을 사용하지 않은 경우와 사용한 경우에 대하여 간암, 폐암 환자 남녀 각 10명씩에 대하여 4D CT 촬영시 조직선량, CTDI 선량, 유효선량을 CT-Expo 프로그램을 이용하여 개개 환자를 평가하였고, 방사선유발사망확률과 수명손실을 PCXMC 프로그램을 이용하여 평가하였다. 조직선량, CTDI 선량의 경우 간암, 폐암 환자의 경우 26.8%, 15.5%의 선량감소가 확인되었고, 방사선유발사망확률과 수명 손실은 간암, 폐암 환자의 경우 16.5%, 19.8%의 위험도 감소를 확인하였다. 본 연구를 통해 CT 촬영 인자를 개개 환자에 적용함으로 조직선량, 유효선량을 평가할 수 있었으며, 나이 및 성별을 고려한 위험인자를 평가할 수 있었다. 선량감소기법으로 제공되는 자동전류조절기능을 사용함으로 간암 및 폐암환자의 경우 21.2%의 선량감소와 18.2%의 위험도 감소가 있음을 확인하였다.

Keywords

References

  1. Mettler FA, Jr., Bhargavan M, Faulkner K, et al.: Radiologic and nuclear medicine studies in the United States and worldwide: frequency, radiation dose, and comparison with other radiation sources--1950-2007. Radiology 253(2):520-531 (2009) https://doi.org/10.1148/radiol.2532082010
  2. Measurements NCoRPa: Ionizing Radiation Exposure of the Population of the United States. Report No. 160 (2009)
  3. Stamm G, Nagel HD: [CT-expo--a novel program for dose evaluation in CT]. Rofo 174(12):1570-1576 (2002) https://doi.org/10.1055/s-2002-35937
  4. ICRP: 1990 Recommendations of the International Commission on Radiological Protection. ICRP Publication 60. . Ann. ICRP 21 (1-3) (1991)
  5. ICRP: The 2007 Recommendations of the International Commission on Radiological Protection. ICRP Publication 103. Ann. ICRP 37 (2-4). (2007)
  6. Tapiovaara M S: PCXMC - A Monte Carlo program for calculating patient doses in medical x-ray examinations (2nd Ed.). STUK-A 231(STUK-A 231) (2008.)
  7. Council NR: Health Risks from Exposure to Low Levels of Ionizing Radiation: BEIR VII Phase 2 (2006)
  8. Thomas D, Darby S, Fagnani F, Hubert P, Vaeth M, Weiss K: Definition and estimation of lifetime detriment from radiation exposures: principles and methods. Health Phys 63(3): 259-272 (1992) https://doi.org/10.1097/00004032-199209000-00001
  9. McCollough CH, Bruesewitz MR, Kofler JM, Jr.: CT dose reduction and dose management tools: overview of available options. Radiographics 26(2):503-512 (2006) https://doi.org/10.1148/rg.262055138